Ported cylinder construction



Aug. 30, 1932. R. CHILTON 1,874,446

P ORTED CYLINDER CONSTRUCTION Filed March 26. 1931 INVENTOR. 201mm(271.17 TON Patented Aug. 30, 1932 Y UNITED STATES PATENT OFFICE ROLANDCHILTON, OF BIDGEWOOD, JERSEY, ASSIGNOR TO WRIGHT AERO NAUTICALCORPORATION, A CORPORATION OF NEW YORK PORTED CYLINDER CONSTRUCTIONApplication filed March 26, 1931. Serial No. 525,494.

This invention relates to ported cylinders, such as are used intwo-cycle internal combustion engines, wherein exhaust or inlet portsare uncovered by the piston during its travel. 7

A prime object of the invention is to achieve good cooling of thecylinder sleeve in the neighborhood of the ports, and particularly toimprove the vconductive path for heat travel from the bars betweenadjacent ports to the cooling medium. In the embodiment illustrated,water cooling is indicated, but it will be understood that the inventionis applicable to air or other cooling means.

A further object of the invention is to provide good cooling for theport zone in a liner type cylinder, wherein a sleeve is inserted in ajacketed casting, which may then be of aluminum or other light alloy,whereby substantial weight saving is effected.v In the prior art,sleeves of uniformthickness have been used whereby the bars arerelatively slender, giving veryslight endwise conductivity'forabstraction of heat. Such slender bars are also subject to distortionwhereby they tend to move out of contact with the cylinder casting, thespace thus formed usually becoming filled with carbon, which is a poorheat conductor. In the present invention, on the contrary, the sleeve isfabricated with an integral collar of relatively great radial extensionthru which the ports are pierced. The cylinder body is formed in twopieces, between which the port belt of the sleeve is firmly pinched byaccurately machined faces, giving intimate thermal contact. Due to thegreat thickness of this port belt and to the preferred circular ports,it will be seen that each bar has in effect a steep taper from themiddle of the port to the root of the bar where it engages the cold wallof the cylinder casting, whereat the surface in contact for each bar ismany times the sectional area of the bar at its mid-point. It will beseen that by these means a greatly improved degree of conductivity fromthe mid-point of each port bar to the cooling medium is aflorded, andthat the joints will not be subjected to opening up due to distortion ofthe parts. In this way the damage to the piston ring, characteristic ofexcessive port bar temperatures, is avoided.

In the prior art the port bars have been formed with longitudinal waterpassages for cooling in the case of the larger cylinders where the lineris not used. Where a liner is desired, as in the present invention,watercooled bars would involve a multiplicity of water joints betweenthe liner and the cylinder which would be subject to leakage troubles.Hollow bars also take up more room, thus detracting from the availableport area. One of the objects of the present invention is to achievegood cooling in a ported cylinder liner by simple means not subject tothe foregoing disadvantages.

Due to the fact that the piston rings pass the ports, these must besubdivided into relatively short circumferential lengths in ordertoprevent the rings from expanding into the ports and striking the edgesthereof. In the drawing, round ports have been shown, altho theinvention is applicable to any desired shape of port.

In the drawing: 4

Fig. 1 is an axial sect-ion thru an engine cylinder embodying theconstruction of this invention, and

Fig. 2 is a plan section on the line 2-2 of Fig,

Referring first to Fig. 1. 1O designates the combustion chamber partofthe cylinder and 12 the lower or base portion respectively pro videdwithjackets 14 16 for a suitable cooling medium. These parts areenlarged to provide the port belt 18 provided with the outlet-port 20 towhich suitable pine not shown) may be secured. The cylinder portions aresecured together at the parting face 22 as by bolts 24 and are further.provided with'accurately machined annular faces 26 and 28 between whichis tightly clamped the collar 30 formed integral with the sleeve orliner 32 which is closely fitted to the bores of the cylinder parts 10and 12. A plurality of ports are formed thru the collar 30 which portsmay be over-run by the piston 42. Suitable water passages are providedinthe jointing face 22 whereat packing rings 44 -vention is equallyapplicable to air cooled cylinders wherein the water jacket would bereplaced by suitable cooling fins.

The operation of the device is as follows: 7 The faces 26 and 28 aremaintained at low temperature by the coolingrncdiurn. The

axial thickness of the collar 30 is such that it is tightly pinchedbetween these faces when the parts are assembled so that an intimatethermal contact is maintained whereby heat is abstracted from the collar30 to the cooling medium, so that the temperature of the collar will besubstantially the same as thatof the faces 26 and 28. It will be seenthat the bars 48' defined between the ports l0 each subtend a large baseof contact with the cooled faces 26 and 28 so that a very direct andefficient conductive path is afforded whereby the temperature gradientaxially of the bars will be slight and the entire port zone of thesleeve will approximate the temperature of the cooled faces 26 and 28.

While I have described my invention in detail in its present preferredembodiment, it will be obvious to those skilled in the art afterunderstanding my invention, that various changes and modifications maybe made therein without departing from the spirit or scope thereof. Iaim in the appended claims to cover all such modifications and changes.

What I claim is:

1. In an engine having ports overrun by a piston, the combination, of acylinder liner having a collar containing the ports and upper and lowerfluid cooled cylinder members fitted to said liner and having faces inintimate thermal contact with said collar.

2. In an engine, in combination, a cylinder comprising a combustionchamber portion and a base portion having faces defining an annular portbelt therebetween, and a lining ing means, a liner engaged in saidcylinder andhaving a collar engaging said annular face and ports thrusaid collar.

6. The combination with a cooled cylinder, of an improved cooling meansfor a ported c linder liner comprising an annular proj ection on theliner containing the ports and secured in intimate thermal contact withthe cylinder. y b I 7. A cylinder comprising a combustion chamber artand a base part defining aport belt there etween having opposed andspaced annular faces, means for cooling said faces, a liner in saidcylinder arts having a collar engaged between said aces and portopenings formed, thru said collar. v F

8. A construction for cooling a ported cylinder comprising incombination, a cylinder having a boreand an annular face, means forcooling the walls of said bore and face, a liner engaged in said boreand having a collar engaging said face and ports formed thru saidcollar.

9. In an engine, a two-partcylinder, a liner for said cylinder, and anannular ported collar formed upon said liner and against which therespective cylinder parts are adapted to bear. I I

10. In an engine, in combination, a cylinder having cooling means andcomprising two parts, each of said parts having a cooperating wallopposed to and spaced from the wall on the other partto provide anannular port belt therebetween, and a. liner for said cylinder partshaving an annular ported collar clamped between said walls.

In testimony whereof I hereunto afix my signature.

ROLAND CHILTON.

sleeve for said portions having a ported annulus engaging said faces.

3. In an engine having a ported cylinder liner to be cooled, aport-containing-collar formed on the liner and comprising a shoulder ofsubstantial area, and a cylinder having an annular face provided withcooling means and in intimate contact with said shoulder;

4. In a cylinder having a liner provided with a plurality of ports,means for cooling 7 the inter-port parts of the liner comprising,

in combination, a port-containing-collar extended from the liner toprovide shoulders of substantial area adjacent tosaid ports, cylindermembers having faces in intimate thermal contact with said shoulders,and means to cool said faces.

5. In an engine, in combination, a cylinder having an annular faceprovided with cool-

